Mithril seeds are a magical type of seed that can be planted almost anywhere to grow some flowers in the ground. On planting the seeds, the player will move one adjacent square then be given the option to pick the flowers. Picking the flowers produces one of 9 different colors of Flowers. It is confirmed that the odds of obtaining black flowers are 2/1,001, and white flowers are 1/1,001.

On 18 March, 2013, along with gambling becoming against the Runescape Rules of Conduct, the way that the seeds worked was mended so that when planted, the appearance of all flowers in the ground now have the same image, but when picked up, then the difference in colors can be seen. The flowers were the main tool for gamblers because of the randomness in which color of flower would grow when the seeds were planted.

A player plants and picks several flowers

The change vastly cut the supply of white and black flowers down. Where it used to be that people could simply plant the seeds until a white or black flower appeared, then picked that flower, now a person looking to produce a black or white flower needs to pick up every single flower that he plants, lengthening the amount of time it takes to find one and making it much more tedious for a player to do.